Technical Field
The present disclosure relates to a method for producing masterbatches. Furthermore, the present disclosure relates to masterbatches obtained by the method according to the present disclosure. Additionally, the present disclosure relates to the use of the masterbatches obtained by the method according to the present disclosure for colouring polymer materials and for equipping polymer materials with functional additives.
Description of the Related Art
Masterbatches are regularly used for the application-specific modification of synthetic materials. In this connection masterbatches are polymer-bound additive concentrates. One advantage of such masterbatches is that they must regularly be added to a polymer material in only very low quantities in order to create the desired colouring or modification. These quantities are regularly in the region of two to five percent. Generally, two classification systems are used for dividing masterbatches. According to one system, masterbatches can be divided into colour, additive and combination masterbatches. This division is function-oriented. According to the other system, masterbatches can be subdivided into universal and polymer-specific masterbatches, with a view to the polymer matrix material to which these masterbatches are added. Due to compatibility problems which arise due to the partial incompatibility of the polymers, which are used on the one hand for the masterbatch and on the other for the polymer matrix material, and which result in de-mixing phenomena and dispersing errors, universal masterbatches are still regularly problematic for many applications, although universal masterbatches would certainly offer considerable potential for rationalisation with regard to storage and logistics. Currently, there are a number of specific masterbatch types for every synthetic material class.
The successful use of masterbatches also lies in the fact that solid-based additives can be present in masterbatch preparations in an either fully or almost fully dispersed state. As a result, dispersive mixing to break up and dissipate agglomerates and aggregates is hardly necessary at all during the production of synthetic materials. Accordingly, no additional dispersing agents are usually required when adding masterbatches to polymer matrix materials. Masterbatches are generally obtained in the form of granules. In this connection, the masterbatches which are in some cases very easy to handle are those in which the granules are pourable and dust-free.
Masterbatches are generally produced according to a single-step or dual-step method. With single-step production, all raw material components are provided and extruded. With the dual-step method, so-called ‘monoconcentrates’ are first produced, which are then mixed once again and, if need be, mixed with additives, before being extruded. The homogeneity of the colour tone in the synthetic material depends on what flow behaviour is achieved in the molten mass, or how well the masterbatch is distributed in the matrix. In many cases, it is not possible, or only to an inadequate degree, to work pigments into a masterbatch while at the same time retaining a homogeneous colouring. For example, pigments produced through dry calcination can regularly only be distributed with a high energy input, and also can usually only be partially distributed in a masterbatch. The term also used here is “hard to disperse” pigments.